Question

I'm working with moto and Python 3.7 to mock some S3 interaction. It appears that moto is working properly if all of the mocking code is contained in the test method. When I move some of the preliminary code to setUp(), the test fails as if setUp() has never run.

import unittest

import boto3
from moto import mock_s3

class BucketFacadeTests(unittest.TestCase):

    @mock_s3
    def setUp(self):
        print('setUp called')
        s3 = boto3.resource('s3', region_name='us-east-1')
        s3.create_bucket(Bucket='bucket')
        key = 'a/b/c/d.txt'
        object = s3.Object('bucket', key)
        object.put(Body='my dog has fleas')

    def do_test(self):
        s3 = boto3.resource('s3', region_name='us-east-1')
        the_object = s3.Object('bucket', 'a/b/c/d.txt')
        string_data = the_object.get()['Body'].read().decode('utf-8')
        self.assertEqual('my dog has fleas', string_data)

    @mock_s3
    def test_bucket_can_be_accessed_with_setup(self):
        self.do_test()

    @mock_s3
    def test_bucket_can_be_accessed_without_setup(self):
        # This does what setUp() should
        s3 = boto3.resource('s3', region_name='us-east-1')
        s3.create_bucket(Bucket='bucket')
        key = 'a/b/c/d.txt'
        object = s3.Object('bucket', key)
        object.put(Body='my dog has fleas')

        self.do_test()

When I don't rely on setUp(), everything runs as expected

Testing started at 07:49 ...
/Users/paul/.virtualenvs/nui-converter/bin/python "/Applications/PyCharm CE.app/Contents/helpers/pycharm/_jb_unittest_runner.py" --target BucketFacade2Tests.BucketFacadeTests.test_bucket_can_be_accessed_without_setup
Launching unittests with arguments python -m unittest BucketFacade2Tests.BucketFacadeTests.test_bucket_can_be_accessed_without_setup in /Users/Paul/as/nui-converter/tests/InventoryLoader
setUp called


Ran 1 test in 0.103s

OK

Process finished with exit code 0

Yet it fails when I do rely on setUp()

Testing started at 07:56 ...
/Users/paul/.virtualenvs/nui-converter/bin/python "/Applications/PyCharm CE.app/Contents/helpers/pycharm/_jb_unittest_runner.py" --target BucketFacade2Tests.BucketFacadeTests.test_bucket_can_be_accessed_with_setup
Launching unittests with arguments python -m unittest BucketFacade2Tests.BucketFacadeTests.test_bucket_can_be_accessed_with_setup in /Users/Paul/as/nui-converter/tests/InventoryLoader
setUp called


Ran 1 test in 0.183s

FAILED (errors=1)

Error
Traceback (most recent call last):
  File "/usr/local/Cellar/python/3.7.1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/unittest/case.py", line 59, in testPartExecutor
    yield
  File "/usr/local/Cellar/python/3.7.1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/unittest/case.py", line 615, in run
    testMethod()
  File "/Users/paul/.virtualenvs/nui-converter/lib/python3.7/site-packages/moto/core/models.py", line 74, in wrapper
    result = func(*args, **kwargs)
  File "/Users/Paul/as/nui-converter/tests/InventoryLoader/BucketFacade2Tests.py", line 27, in test_bucket_can_be_accessed_with_setup
    self.do_test()
  File "/Users/Paul/as/nui-converter/tests/InventoryLoader/BucketFacade2Tests.py", line 22, in do_test
    string_data = the_object.get()['Body'].read().decode('utf-8')
  File "/Users/paul/.virtualenvs/nui-converter/lib/python3.7/site-packages/boto3/resources/factory.py", line 520, in do_action
    response = action(self, *args, **kwargs)
  File "/Users/paul/.virtualenvs/nui-converter/lib/python3.7/site-packages/boto3/resources/action.py", line 83, in __call__
    response = getattr(parent.meta.client, operation_name)(**params)
  File "/Users/paul/.virtualenvs/nui-converter/lib/python3.7/site-packages/botocore/client.py", line 357, in _api_call
    return self._make_api_call(operation_name, kwargs)
  File "/Users/paul/.virtualenvs/nui-converter/lib/python3.7/site-packages/botocore/client.py", line 661, in _make_api_call
    raise error_class(parsed_response, operation_name)
botocore.errorfactory.NoSuchBucket: An error occurred (NoSuchBucket) when calling the GetObject operation: The specified bucket does not exist


Process finished with exit code 1

Am I doing something wrong or pushing moto beyond its limits?

Answer 1

问题是您将ock_s3装饰器直接应用于setUp()方法和test methods。这会导致在单独的模拟s3环境中，因此不会共享在setUp()方法中所做的任何事情。

解决方案是将@mock_s3装饰器应用于整个BucketFacadeTests类。

下面的代码应该可以正常工作。

import unittest

import boto3
from moto import mock_s3

@mock_s3
class BucketFacadeTests(unittest.TestCase):


    def setUp(self):
        print('setUp called')
        s3 = boto3.resource('s3', region_name='us-east-1')
        s3.create_bucket(Bucket='bucket')
        key = 'a/b/c/d.txt'
        object = s3.Object('bucket', key)
        object.put(Body='my dog has fleas')

    def do_test(self):
        s3 = boto3.resource('s3', region_name='us-east-1')
        the_object = s3.Object('bucket', 'a/b/c/d.txt')
        string_data = the_object.get()['Body'].read().decode('utf-8')
        self.assertEqual('my dog has fleas', string_data)

    def test_bucket_can_be_accessed_with_setup(self):
        self.do_test()

    def test_bucket_can_be_accessed_without_setup(self):
        # This does what setUp() should
        s3 = boto3.resource('s3', region_name='us-east-1')
        s3.create_bucket(Bucket='bucket')
        key = 'a/b/c/d.txt'
        object = s3.Object('bucket', key)
        object.put(Body='my dog has fleas')

        self.do_test()

Moto does not work with python unit test setUp() call

1 个答案: